The invention relates to a brewing chamber of a coffee machine and a coffee machine.
Coffee machines operate according to different principles. The most common models are the so-called pressureless coffee machines such as are known, for example, from DE 296 10 393 U1. In these water flows from a storage container into an electrically heatable pipe. Particularly as a result of the evolution of steam in this pipe, heated water is then pushed through a riser to an outlet via which the heated water then drips into a coffee filter. The filter coffee, for example, can then flow from this coffee filter at atmospheric pressure into a pot.
In contrast, in espresso machines such as those disclosed in DE 197 01 033 A1, an elevated pressure prevails in the area of the coffee grounds. This is achieved by supplying water, for example, from a water container or another water supply to a pump which then supplies the water at high pressure via an electrically heatable area to a coffee grounds receiving device. This coffee grounds receiving device generally comprises a filter for receiving the coffee. In order to generate the high pressure in the area of the coffee grounds, during operation the coffee grounds receiving device is located in an area which is sealed towards the atmosphere, which is designated as a pressure chamber or brewing chamber.
In another type of coffee machine such as those described in WO 01/15582 or EP 1 050 258 A1, it is provided to first transfer the water for preparing the coffee from a water container into a heatable intermediate container. From this intermediate container the heated water is passed to a pump from which it is supplied at elevated pressure, for example 2 to 3 bar, to a coffee grounds receiving device. In this case, it is provided that the coffee is not introduced into the coffee grounds receiving device in loose form as coffee grounds but is inserted in a retainer in the form of a coffee pad, that is, in compacted form surrounded by filter paper. The retainer with a retainer cover via which water is supplied can form a sealed pressure chamber. At the same time, the retainer for the coffee pads is allocated a plurality of functions. Firstly, the retainer provides a sealing surface so that a pressure chamber can be formed. Moreover, the retainer has an outlet opening from which the coffee can emerge. Furthermore, the coffee pad should be mounted in the retainer in a manner such that flow through the coffee pad is not impeded. Such a coffee machine occupies an intermediate position between a conventional pressureless coffee machine and an espresso machine.
In the coffee machine disclosed in WO 01/15582 A1 the coffee pads are inserted in a lower portion of the brewing chamber and the upper portion of the brewing chamber can be folded onto the lower portion by the user by means of a hinge. An engaging connection between the two housing portions which are hinged relative to one another ensures sealing of the brewing chamber.
In the coffee machine known from EP 1 050 258 A1 the coffee pad is inserted in a pulled-out drawer and is then brought into the brewing position by pushing in the drawer. For sealing the brewing chamber, a brewing chamber upper portion is automatically moved over the coffee pad from above before the brewing process. After the brewing process, the coffee pads are automatically removed inside the coffee machine in a collecting container. Particularly as a result of the motor-driven components of the coffee machine, this is very complex and therefore expensive to produce.